Version 3.1 features:
* monochrome launcher icon and predictive back gesture for Android 12,
* Material You theme with system colours,
* new search bar,
* searching by Open Location Code,
* gliding instead of jumping in minimap,
* Polish and Italian translations,
* multiple feeds handling,
* QR codes in Metropolis GZM,
* searching by line (and picking stops on graphs),
* dependency updates, bug fixes, and some code refactor.